Recently, with advancement in digital techniques used in electric devices, non-volatile memory devices having a large capacity have been actively developed for storage of data such as music, images, and other information.
As one next-generation non-volatile memory device, a non-volatile memory device (called ReRAM) has been focused on which includes a variable resistance memory device (variable resistance element) having a resistance value variable with application of an electric pulse and holds the state. The variable resistance non-volatile memory device has an advantage of being able to be consistent with conventional normal semiconductor processes and to be further refined.
For example, Patent Literature 1 discloses a structure in which a variable resistance element and a diode are arranged in series in a perpendicular direction, a variable resistance film is formed to be a variable resistance element in a contact hole, and the diode is formed above the contact hole, for allowing the diode to have an effective area larger than the effective area of the variable resistance element.
Patent Literature 2 discloses a cross-point structure as a structure for realizing high integration of non-volatile memory devices. The non-volatile memory device having a cross-point structure disclosed in Patent Literature 2 includes a memory cell array including a plurality of memory devices each having a variable resistance element. The memory devices are arranged in via holes in a cross-point area in which a plurality of first lines and a plurality of second lines are arranged orthogonal to each other. In addition, in each memory device, elements each having a non-linear current-voltage characteristic (non-linear elements or current steering elements) are arranged in series. These elements having the non-linear current-voltage characteristic selectively activate given ones of the memory devices in the memory cell array. More specifically, for example, use of diodes of a metal-insulator-metal (MIM) type as current steering elements allows the memory devices to perform bi-directional current steering.